1. Field of the Invention
The present invention relates to a radiographic image processing apparatus, a radiographic image processing method, a computer program for achieving that radiographic image processing method, and a computer-readable recording medium for recording that computer program. More particularly, the present invention is suitable to be used in a process of connecting plural digital radiographic images obtained by photographing an identical patient.
2. Related Background Art
In the field of radiotherapy, there is a possibility that a large area incapable of being photographed and held within one film is diagnosed such as scoliosis or the like. In that case, a so-called stitching process of physically connecting plural images respectively photographed and held on plural films is performed, the physically connected images are restored as a global image, and then actual diagnosis is performed based on the obtained global image.
Incidentally, in recent years, digital X-ray image photographing apparatuses such as a CR (computer radiography) apparatus, a DR (digital radiography) apparatus and the like for obtaining digital radiographic images have come into wide use. In such circumstances, there are many requests for performing the stitching process to the digital radiographic images obtained by the digital X-ray image photographing apparatuses.
There have been known Japanese Patent
Application Laid-Open Nos. 2002-44413 and 2002-94772 as the conventional arts of performing the stitching process of plural digital radiographic images. These conventional arts are directed to the technology which is useful in a case where plural radiographic cassettes are prepared and plural radiographic images obtained by emitting a single X-ray to the films respectively held in these cassettes are connected with others.
More specifically, in Japanese Patent Application Laid-Open No. 2002-94772, a relatively large subject such as a femur or the like is photographed to obtain plural digital radiographic images of the femur, and, in case of connecting the obtained digital radiographic images with others, parallel and rotational image shifts are corrected by appropriately using a histogram and an identification mark of each of these images.
However, in a case where the stitching process is performed to the images of an area such as a backbone area including numerous similar small bones, when a histogram or the like is calculated as mentioned above, there is a fear that a joining portion where the successive radiographic images are connected with each other is erroneously recognized. For this reason, in an action such as diagnosis in which highly accurate image reading is necessary, it is necessary for a doctor to perform the actually stitching process to the plural digital radiographic images by repeating the parallel and rotational shifts of these images.
On one hand, in order to achieve the stitching process to plural digital images not limited to the digital radiographic images, it is likewise necessary to perform parallel shifts and rotational shifts of arbitrary angles respectively to these images. In that case, although it is possible to display the parallel shift in real time because its calculation amount is small, it is difficult to display the rotational shift in real time because its calculation amount is large.
In case of performing the rotational process of an image by an arbitrary angle, for example, by using PowerPoint™ of Microsoft, a bitmap image, a JPEG (Joint Photographic Experts Group) image and the like cannot be rotated, but only a figure can be rotated. In any case, in case of rotating the figure by PowerPoint™, there are two methods of adding a rotational angle, that is, one for directly inputting the rotational angle by using numerical values, and the other for displaying only the contour line of the figure on a UI (user interface) to cause a user to add the rotational angle with use of a mouse or the like on the UI.
Besides, by using Photoshop™ of Adobe, a bitmap image or the like can be rotated, but in that case, only the contour line of the digital image is merely displayed.